Bacteria are an important group of natural antagonists of plant-parasitic nematodes. Bacteria are distributed broadly, have diverse modes of action, and have broad host ranges (Tian, B. et al.). They exhibit diverse modes of action against nematodes that include parasitism, production of toxins, antibiotics, or lytic enzymes; induce systemic resistance, and promote plant health (Aatlen, P. M. et al.; Kerry, B. R. 2000; Kerry, B. R. 1987; Siddiqui, Z. A. et al.; Stirling, G. R. 1991; Tian, B. et al.; Van Loon, L. C. et al.). Furthermore, bacteria can be in direct contact with the entrance sites of the nematodes and influence root exudates that can affect the nematode development (Sikora, R. A. 1992). The genera Pasteuria, Pseudomonas, and Bacillus have shown promising potential for nematode biocontrol (Meyer S. L. F; Siddiqui, Z. A. et al.; Stirling, G. R.; Tian, B. et al.).
Bacillus firmus strain GB-126 is a nematode biocontrol agent registered initially in a bionematicide in Israel under the trade name of BIONEM® WP (Blachinsky, D. et al.; Keren-Zur et al.). This formulation was shown to reduce galling index caused by Meloidogyne spp. on cucumber and tomato plots (Keren-Zur et al.). Also, under field conditions, suppression of Meloidogyne spp. was observed within 2 months of transplanting cucumbers and continued through the end of the experiments (Giannakou, O. I. et al., 2004). Control provided by B. firmus GB-126 was less effective than the soil fumigant dazomet. However, its combination with soil solarization improves nematode control giving results similar to dazomet use (Giannakou, O. I. et al. 2007). Furthermore, when B. firmus GB-126 was evaluated in tomato seedlings in the greenhouse, it reduced gall formation by 91%, final nematode population by 76%, and the number of M. incognita eggs by 45% (Terefe, M. et al.).
In other study, a formulation of B. firmus that contains seaweed extract (BIONEM® L) was able to reduce Helicotylenchus spp. and Tylenchorhynchus spp. in golf greens (Wick, R. L. 2006). Furthermore, synergism of B. firmus with other nematode biocontrol agents has been reported to improve nematode reduction (Mendoza, A. R. et al. 2009). In banana, B. firmus was evaluated against R. similis and applied in combination with F. oxysporum and P. lilacinus, which reduced the infection of this migratory endoparasitic nematode (Mendoza, A. R. et al. 2009). Under in vitro conditions B. firmus was evaluated against the plant parasitic nematodes Radopholus similis, Meloidogyne incognita, and Ditylenchus dipsaci. Bacillus firmus produced bioactive secondary metabolites that were toxic to these nematode juveniles and reduced egg hatching (Mendoza, A. R. et al. 2008).
Thus, previous studies have demonstrated the antagonistic effect of bioactive secondary metabolites of Bacillus firmus GB-126 against plant parasitic nematodes. Nevertheless, the types of secondary metabolites and enzymatic properties involved and the role of possible induction of plant resistance have not been evaluated. Fewer and fewer traditional nematicide are available today and many that are available are very expensive or not environmentally and user friendly. Identification of a biological means to protection plants from pathogenic nematodes fits well into today's integrated pest management platform for agriculture. Understanding the single or multiple modes of actions of a biocontrol microbe can assist in the optimization of the growth of the microbe prior to formulating into a commercial product. Studies that evaluate the purpose of the various secondary metabolites can define which of the many metabolites should be optimized during the growth of the microbe. There are means available to optimize the growth media of the microbe to enhance production of one metabolite or another.
An object of the present invention is to provide a novel entity having anti-nematodal activity derived from Bacillus firmus bacteria selected from the group consisting of isolated biosurfactant, isolated protease, isolated amylase, isolated lipase, and isolated cellulase, is disclosed. Another object is to provide for compositions comprising the same. Another object is to provide for methods of making the same.
A further object is to provide for methods of controlling plant-parasite nematode, and methods of protecting plants.